Barangay Cayus

Barangay Cayus forms part of Quirino, a municipality in Ilocos Sur, and is classified as a small barangay.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Cayus had a population of 860. This made it the 6th largest of 9 barangays in Quirino by population, placing it in the middle tier of the municipality. Residents of Barangay Cayus accounted for approximately 9.24% of the total population of Quirino, which stood at 9,306 in the same census year.

The barangay recorded 721 residents in the 2015 intercensal count and 860 residents in the 2020 Census — a net change of +19.3%, consistent with a growing settlement. The Philippine Statistics Authority classifies Barangay Cayus as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Quirino is a municipality comprising 9 barangays, and serves as the governing unit directly responsible for local services in Barangay Cayus, including public health, sanitation, peace and order, and civil registration. Within the wider province of Ilocos Sur, which contains 768 barangays across its component cities and municipalities, Barangay Cayus ranks 344th by 2020 population. Ilocos Sur is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

The barangay's legislative and executive affairs are handled by a Punong Barangay and the Sangguniang Barangay, elected nationwide during the Barangay and SK Elections. The next BSKE is scheduled for Monday, November 2, 2026, following the synchronized election schedule set by COMELEC Resolution No. 11191.